Fuel system apparatus and method

ABSTRACT

In a fuel system of an engine having a fuel tank, carburetor, and inlet and outlet manifolds, means are provided for passing fuel vapors into an absorber for retention therein and delivery into the intake manifold during starting of the engine and for a period thereafter. The flow of the fuel vapor from the absorber is terminated and fuel delivery from the carburetor into the intake manifold is initiated in response to an increase in the temperature of the exhaust manifold.

United States Patent Alquist Oct. 9, 1973 54] FUEL SYSTEM APPARATUS AND METHOD 3,685,504 8/1972 Torazza 123/130 3,572,013 3/1971 Hansen 123/136 [75] Inventor: Henry E. Alquist, Bartlesville,

Okla.

[73] Assignee: Phillips Petroleum Company,

Bartlesville, Okla.

Primary Examiner-Laurence M. Goodridge Assistant Examiner-Cort Flint Attorney-J. Arthur Young et al.

[ ABSTRACT In a fuel system of an engine having a fuel tank, carburetor, and inlet and outlet manifolds, means are provided for passing fuel vapors into an absorber for retention therein and delivery into the intake manifold during starting of the engine and for a period thereafter. The flow of the fuel vapor from the absorber is terminated and fuel delivery from the carburetor into the intake manifold is initiated in response to an increase in the temperature of the exhaust manifold.

10 Claims, 2 Drawing Figures [22] Filed: Nov. 24, 1971 21 Appl. No.: 201,720

[52] U.S. Cl. 123/136 [51] Int. Cl. F02m 17/08, F02b 77/00 [58] Field of Search 123/136 [56] References Cited UNITED STATES PATENTS 3,563,007 2/1971 Clarke 123/136 3,680,318 8/1972 Nakajima 123/136 3,093,124 6/1963 Wentworth... 123/136 3,456,635 7/1969 Hervert 123/136 3,191,587 6/1965 Hall 123/136 t 1 a A B SORBE R AIR CLEANER AIR CLEANER LL CARES.

INTAKE MANIFOLD HEAT EXCHANGER FUEL TANK I2 PMENIEH 9W3 3,763,839

M ABSORBER AIR CLEANER AIIR CLEANER HEAT 48 EXCHANGER 34 22\ A B. I c R 38 INTAKE MANIFOLD 2 ill FUEL TANK INVENTOR.

H. E. ALQUIST BY 11 F/GZ a ATTORNEYS FUEL SYSTEM APPARATUS AND METHOD lt is desirable to provide a fuel system for an engine which will provide for more complete combustion of the fuel delivered to the engine during-initial starting of the engine and for a period thereafter until the temperature of said engine is increased to a preselected value. It has been found that the exhaust gases emitted from an engine during startup and for a short running period thereafter have a high concentration of uncombusted hydrocarbons and other air polluting constituents. It has also been found that if the fuel delivered to the cold engine, during startup and a following operational period thereof, is a vapor recovered from the liquid fuel normally utilized by the engine, the concentration of the air polluting constituents discharged from the engine is markedly reduced.

In summary, this invention therefore resides in an improved fuel system apparatus and method which has an absorber for recovering fuelvapors from the fuel tank of the system and controllably delivering these vapors into the intake manifold of the engine during startup operations of the engine and for a period thereafter sufficient for said engine to increase in temperature to a preselected value.

Other aspects, objects, and advantages of the present invention will become apparent from a study of the disclosure, the appended claims, and the drawings.

The drawings are diagrammatic views of the apparatus of the instant invention and a portion of the engine upon which utilized.

FIG. 1 shows the apparatus of the invention and FIG. 2 shows an enlarged diagrammatic view of the choke plates and operating elements of the apparatus.

Referring to FIG. 1, an engine (not shown) as known in the art, has intake manifold 2 and an exhaust manifold 4. The intake manifold 2 is connected to a carburetor 6 which in turn is connected to a fuel line 8 through a fuel pump 10 to a fuel tank 12. As is further known in the art, the carburetor 6 can be connected to an air cleaner 14 for the passage of air into contact with fuel in the carburetor for subsequent delivery of the resultant mixture into the intake manifold 2 for subsequent combustion within the engine and for subsequent passage of exhaust gases of combustion through the exhaust manifold 4. A throttle valve 16 is associated with carburetor 6 for controlling the flow rate of the mixture into the intake manifold 2.

An absorber 18 having an absorbent 20 positioned therein is connected in fluid communication with the intake manifold 2 by a fuel vapor conduit 22. A vaporconduit 24 is connected to an upper portion of the fuel tank 12 and to the absorber 18, for example through said fuel vapor conduit 22, for passing fuel vapors from the tank 12 into the absorbent 20,for retention ofa portion of said fuel vapors therein.

Means are associated with the-fuel vapor conduit 22 for selectively passing fuel vapors from the absorber 18 into the intake manifold. As better seen in FIG. 2, said means comprises a first choke plate 26 movably positioned in the fuel vapor conduit 22 and a second choke plate 28 movably associated with the carburetor 6. Each of the choke plates 26, 28 is movable between a first position at which each choke plate is not sealing its respective passageway and a second position at which each choke plate is sealing its respective passageway. The choke plates 26, 28 are connected one to the other for synchronously opposed moving relative to the other. When the first choke plate 26 is at its first position, the second choke plate 28 is at its second position, and when the first choke plate 26 is at its second position, the second c'hoke plate 28 is at its first position.

FIG. 2 shows an example method for connecting the first and second choke plates 26, 28 one to the other for opposed synchronous movement. Here each choke plate 26, 28 is pivotally connected to a connecting rod 30. The connecting rod is connected to a thermostati-. cally operated spring 32 which in turn is associated with line 34 which is utilized for passing gas from the 'exhaust manifold 4 to the spring 32 for maintaining the temperature of said spring at a temperature representative of the temperature of the exhaust manifold or the gases therein. It should be understood that the choke plates 26, 28 can be synchronously moved between their first and second positions in response to said representative temperature by other apparatus such as, for example, an electrical system, motor, and gear arrangement.

In order to assure a ready supply of absorbed fuel in the absorbent 20, a heat exchanger 36 can be connected to the fuel line 8 through a three-way valve 38, for example, for selectively passing a fuel stream to the heat exchanger. The heat exchanger 36 has a vapor outlet 40 in communication with the vapor conduit 24 via line 42 for passing fuel vapors from the heat exchanger 36 to the absorbent 20. Weighing-signalling element 44 such as, for example, bonded-strain gages with millivoltmeter or potentiometer control means is associated with the absorbent 20 within the absorber 18 for weighing the absorbent and fuel vapor therein and delivering a signal to a controller of the valve 38 in response to said measurement being other than within a preselected weight range. The temperature valve means connected in series to the water cooling system going to the heat exchanger and being set at different actuation temperatures can be utilized to replace the weighing-signalling element.

The absorbent 20 of the absorber 18 can be for example treated silica gel, treated in accordance with U. S. Pat. No. 2,700,06l, or charcoal, preferably charcoal. The absorbent 20 is also preferably of a configuration to expose a large surface for contacting and absorbing vapors coming in contact therewith.

In the method of this invention, the first choke plate 26 is at its first position and the second choke plate 28 is at its second position as shown in FIG. 1 when the engine is cold and not running for example. The absorbent contains fuel constituents which have been absorbed during previous operation of the engine. As the engine is started, air is moved through the absorbent 20 during which passage therethrough fuel vapors are moved into the inlet manifold for starting of the engine with only fuel vapors. During startup and initial running of the engine, the flow rate of the fuel vapors and air into the inlet manifold 2 are controlled by throttle valve 48.

As the engine continues to run, the exhaust manifold 4 increases in temperature which increases the temperature of the spring 32 for example by the transfer of heat from the exhaust manifold 4 through line 34. As the thermostatically controlled spring increases in temperature, it causes the first choke plate 26 to move from its first position and the second choke plate 28 to move synchronously with the first plate 26 from its secnd position to its first position. During this synchronous movement, the flow of vapor fuel from the absorbent 20 into the inlet manifold 2 is gradually decreased and finally terminated when the temperature of the spring reaches a preselected value. During closing of the first choke plate 26, the second choke plate 28 is synchronously opened in response to the increase in the temperature of the spring. In this manner, the fuel for the operation of the engine is changed from fuel vapor from the absorbent 20 to fuel from the carburetor 6. The engine thereafter continues to operate on fuel from the fuel tank 12 via the carburetor 6.

The temperature at which said first choke valve 26 begins to move from the first toward the second position and at which said first valve 26 reaches its second position is dependent upon the size and operational characteristics of the apparatus and the engine and are variables which can easily be determined by one skilled in the art. Said individual skilled in the art can then easily construct the choke valves 26, 28 to function in the desired manner.

As fuel passes from the absorbent 20, the weight of said absorbent decreases. At a preselected lower weight limit as detected by the element 44, a signal can be delivered to valve 38 which assists in replenishing the absorbent fuel supply by passing fuel to the heat exchanger for discharging additional fuel vapor into conduit 24. When the weight, as measured by the element 44, reaches a preselected maximum value a signal can be delivered to the valve 38 for switching the valve and terminating the passage of a fuel stream to the heat exchanger 36. In an example system, the heat exchanger can be connected in the water circulating system of the engine and said water be utilized as the heating medium thereof. The maximum and minimum limits of the element 44 are dependent upon absorbent size and can be easily determined by one skilled in the art. Where charcoal is the absorbent, the fuel capacity of the charcoal has been found to be about 13 percent of the weight of the charcoal. With an automobile engine, approximately lOO-l50 grams of hydrocarbon are taken from the absorbent during a typical startup and initial operational period of the engine. Therefore, 1,000-1 ,500 grams of absorbent are necessary.

Other modifications and alterations of this invention will become apparent to those skilled in the art from the foregoing discussion and accompanying drawing, and it should be understood that this invention is not to be unduly limited thereto.

1 claim:

1. A fuel system of a combustion zone having an exhaust manifold, comprising:

a fuel tank;

an intake manifold;

an absorber having an absorbent therein;

first means for passing fuel from the tank, mixing air with the fuel, and passing a resultant fuel-air mixture into the manifold;

second means for passing fuel vapor from the tank into contact with the absorbent;

third means for passing fuel vapor from the absorbent into the manifold; and

fourth means for selectively passing fuel vapor from the absorbent into the manifold and preventing the passage of the mixture into the manifold in response to initiation of combustion zone operation and preselected first, low temperature conditions of the exhaust manifold, passing the mixture and fuel vapor from the absorbent into the manifold in response to second, preselected medium temperature conditions of the exhaust manifold, and passing the mixture into the manifold and preventing the passage of fuel vapor from the absorber into the manifold in response to third, preselected higher temperature conditions of the exhaust manifold.

2. A fuel system, as set forth in claim 1, wherein the fourth means comprises:

a first choke plate positioned in the third means and being movable between a first position at which the absorbent is in communication with the manifold and a second position at which the first choke plate is obstructing said communication; and

a second choke plate associated with the first means and connected to the first choke plate for synchro-' nous movement therewith.

3. A fuel system, as set forth in claim 2, including a weighing-signalling means for measuring the weight of the absorber and materials contained therein and delivering a signal responsive to said measurement being less than a preselected value; and

means for increasing the rate of vapor passing to the absorbent in response to said signal.

4. A fuel system, as set forth in claim 1, including a weighing-signalling means for measuring the weight of the absorber and materials contained therein and delivering a signal responsive to said measurement being less than a preselected value; and

means for increasing the rate of vapor passing to the absorbent in response to said signal.

5. A'fuel system, as set forth in claim 3, wherein the first choke plate is connected to a thermostatically operated spring for moving the first choke plate between the first and second positions in response to the temperature of said spring; and

means for maintaining the temperature of said spring at a temperature representative of the temperature of the combustion gas exhaust manifold.

6. A fuel system, as set forth in claim 1, wherein the combustion zone comprises an engine.

7. A method, for operating a fuel system of a fuel combustion zone having a fuel tank, intake and exhaust manifolds, an absorber having absorbent and being connected in fluid communication with the fuel tank and the intake manifold, and a carburetor connected to the fuel tank and the intake manifold, comprising:

passing fuel vapors from the absorber into the intake manifold and preventing the passage of fluid from the carburetor into the intake manifold for initiating combustion and increasing the temperature of the exhaust manifold to a preselected value;

controllably passing the fuel vapor from the absorber into the intake manifold and fuel from the carburetor into the intake manifold in response to second preselected medium temperatures of the exhaust manifold; and

passing the fuel' from the carburetor into the intake manifold and preventing the passage of fuel vapor from the absorber into the intake manifold in response to the temperature of the exhaust manifold being greater than a preselected value.

8. A method, as set forth in claim 7, including measuring the weight of the absorber and materials contained therein;

erated spring for moving the first choke plate between the first and second positions in response to the temperature of said spring; and

means for maintaining the temperature of said spring at a temperature representative of the temperature of an associated combustion gas exhaust manifold. 

1. A fuel system of a combustion zone having an exhaust manifold, comprising: a fuel tank; an intake manifold; an absorber having an absorbent therein; first means for passing fuel from the tank, mixing air with the fuel, and passing a resultant fuel-air mixture into the manifold; second means for passing fuel vapor from the tank into contact with the absorbent; third means for passing fuel vapor from the absorbent into the manifold; and fourth means for selectively passing fuel vapor from the absorbent into the manifold and preventing the passage of the mixture into the manifold in response to initiation of combustion zone operation and preselected first, low temperature conditions of the exhaust manifold, passing the mixture and fuel vapor from the absorbent into the manifold in response to second, preselected medium temperature conditions of the exhaust manifold, and passing the mixture into the manifold and preventing the passage of fuel vapor from the absorber into the manifold in response to third, preselected higher temperature conditions of the exhaust manifold.
 2. A fuel system, as set forth in claim 1, wherein the fourth means comprises: a first choke plate positioned in the third means and being movable between a first position at which the absorbent is in communication with the manifold and a second position at which the first choke plate is obstRucting said communication; and a second choke plate associated with the first means and connected to the first choke plate for synchronous movement therewith.
 3. A fuel system, as set forth in claim 2, including a weighing-signalling means for measuring the weight of the absorber and materials contained therein and delivering a signal responsive to said measurement being less than a preselected value; and means for increasing the rate of vapor passing to the absorbent in response to said signal.
 4. A fuel system, as set forth in claim 1, including a weighing-signalling means for measuring the weight of the absorber and materials contained therein and delivering a signal responsive to said measurement being less than a preselected value; and means for increasing the rate of vapor passing to the absorbent in response to said signal.
 5. A fuel system, as set forth in claim 3, wherein the first choke plate is connected to a thermostatically operated spring for moving the first choke plate between the first and second positions in response to the temperature of said spring; and means for maintaining the temperature of said spring at a temperature representative of the temperature of the combustion gas exhaust manifold.
 6. A fuel system, as set forth in claim 1, wherein the combustion zone comprises an engine.
 7. A method, for operating a fuel system of a fuel combustion zone having a fuel tank, intake and exhaust manifolds, an absorber having absorbent and being connected in fluid communication with the fuel tank and the intake manifold, and a carburetor connected to the fuel tank and the intake manifold, comprising: passing fuel vapors from the absorber into the intake manifold and preventing the passage of fluid from the carburetor into the intake manifold for initiating combustion and increasing the temperature of the exhaust manifold to a preselected value; controllably passing the fuel vapor from the absorber into the intake manifold and fuel from the carburetor into the intake manifold in response to second preselected medium temperatures of the exhaust manifold; and passing the fuel from the carburetor into the intake manifold and preventing the passage of fuel vapor from the absorber into the intake manifold in response to the temperature of the exhaust manifold being greater than a preselected value.
 8. A method, as set forth in claim 7, including measuring the weight of the absorber and materials contained therein; delivering a signal responsive to said measurement being less than a preselected value; and increasing the rate of vapor passing from the fuel tank to the absorber in response to said signal.
 9. A method, as set forth in claim 7, wherein the combustion zone is an engine.
 10. An apparatus, as set forth in claim 2, wherein the first choke plate is connected to a thermostatically operated spring for moving the first choke plate between the first and second positions in response to the temperature of said spring; and means for maintaining the temperature of said spring at a temperature representative of the temperature of an associated combustion gas exhaust manifold. 